1. Technical Field
The present invention relates to a circuit device, an oscillator, an electronic apparatus, a vehicle, and the like.
2. Related Art
Hitherto, temperature-compensated oscillators called temperature compensated crystal oscillators (TCXO) have been known. The TCXO is used as a reference signal source or the like in, for example, a portable communication terminal, a GPS-related device, a wearable device, an on-vehicle device, or the like.
The TCXO includes an ATCXO which is an analog type temperature-compensated oscillator and a DTCXO which is a digital type temperature-compensated oscillator. As the related art of the ATCXO, a technique disclosed in JP-A-2012-199631 is known. As the related art of the DTCXO, a technique disclosed in JP-A-64-82809 is known.
A digital type oscillator such as a DTCXO has advantages in terms of low power consumption and the like, as compared to an analog type oscillator such as an ATCXO. For example, in the ATCXO, a large amount of current to be consumed flows in an analog circuit of a circuit device thereof. Particularly, in the ATCXO, when there is an attempt to increase the order of an approximation function in a temperature compensation circuit (approximation function generation circuit) which is an analog circuit or reduce noise by increasing a current flowing to a transistor of an analog circuit in order to improve frequency accuracy, power consumption is drastically increased. For this reason, there is a problem that it is difficult to realize both an improvement in frequency accuracy and low power consumption.